mywot.comは安全ですか？

OK technically safe, and indeed a good idea. There are some flies in the ointment in the shape of empowered users who can follow their own agenda and vote down or up sites on the basis of opinion rather than technical safety or reliability. By and large most sites you would expect to be OK are marked that way - and the converse. However its not perfect, its not even democracy.

This addon associates all subdomains with the main domain. Free hosted websites reflect the same ratings as their main host. The hosting service may be full of ads, but that doesn't mean an individuals free or paid for subdomain does. It doesn't make their sites bad in anyway and they SHOULD NOT share the same rating. This addon is seriously ridiculous and needs some work. Thousands of sites are likely red-ringed for no reason. Keeping your users safe from ads and annoying website owners everywhere. Good job. Not.